Friction shock-absorbing mechanism



May 25, 1926. 1,585,678

J. F. ocoNNoR FRICTION SHOCK ABSORBING.' MCHANISM lil lil caries..

J'H F. OCONNR, GF CIGG, SLLINOS, SSIS-NGE, BY MESNE ASSGNMENTS, TO

PGBATIO BELAVJARE.

Application ered any e,

This invention relates to improvements in friction shoclr-absoibing;` mechanisms.

@ne object of the invention is to provide a friction shock absorbing mechanism especially adapted for railway draft riggings uuierein are obtained high capacity, and an graduated action with a preliminary movement for a predetermined portion of the stroke with much greater resistance during the balance of the stroke.

il. more specilic object of the invention is to provide a mechanism of the character indicated having an easy preliminary action for cushioning the more numerous relatively small shocks with an ultimate higher capacity, thereby adaptingv the mechanism esce cially for passenger car equipment.

The invention furthermore,consists in the improvements, parts and devices, and in the novel combinations ofthe parts and devices herein shown, described and made the subject of claims.

lu the drawings forming a part of this specification, Figure l is a horizontal, longi tudinal, sectional view of a portion of a railway draft rigging showing my improvements in connection therewith. `Figure 2 is a front end ele ration of the friction shock` absorbing'mechanism proper. Figure 3 is a vertical, transverse, sectional view of the shock absorbing mechanism proper corre* sponding` to the line 8 3 of Figure l. Figure is a broken, horizontal, sectional view, similar to Figure l, but illustrating the position assumed by the parts after an initial portion of the compression stroke. And rigure is a detail perspective of one of the pressure-transmitting auxiliary wedge elements.

ln said drawings, lO-l() denote the. usual dratt sills of a car under'frame to the inner faces of which are secured front and rear stop lugs 'l1-11, of usual construction. A portion ofa drawbar is indicated at l2, the saine being operatirely associated with the shock absorbing mechanism proper byv a hooded cast yolre 13 within which isdisposed said iechanismand a mainr front follower lil. The yolre and'parts therewithin are supported inoperative position by a detachable saddle plate l5;

rVl improved .shock .absorbingV mechanism p-ro'perfconrprises, broadly, a. combined fric# sexier no. eosee.

tion shell and spring cage casting A; a pair of friction-shoes B-B; a central wedge member or block C; a pair of pressure-transmitting auxiliary wedge members D-D; a spring resistance coniprising an outer coil E and an inner coil l?, two spring followers G andrl; and a retainer boltv J.

The casting A is of substantially rectangular form at its front or outer end having top and bottom walls l6-l6 and side walls 17e-li'. A friction shell of rectangular form thus formed, the side walls-17 havingtheir inner faces providing` longitudinally extending flat friction surfaces 18 which are oonverged inwardly of theshell.l At the inner end of the shell proper, the casting is made of reduced section to provide a spring cage 19 and in which the twofspring coils are ioused and maintained in center. Atit's inner end the'casting A has an integral transverselyv extending wall 2O laterally extended and suitably reinforced to adapt it to act as the rea'r follower of the mechanism.

rThe two opposed friction-shoes B are of. like construction and each is preferably in the formof a cored'casting having an outer flat friction surface 2l cooperable with the corresponding adjacent shell friction sur'- face 1S, and an inclined wedge face 22, the two wedge faces converging inwardly of the shell and extending at an angle of preferably 4150 with respect to the artis of the mechanism. rlransverse shoulders are formed at the inner ends of the wedge sections of the shoes as indicated at 23 and against' which bears the spring follower G. The spring follower G is engaged by the' front' end of the outer heavy coil lll only of' the spring resistance and is centrally apertured as indicated at 24: to loosely receive therewithin the thicker second spring follower El which engages the front end-of the inner coil F, only.

rlhe central wedge member or block C is in the form of acored casting having a` front transverse bearing 'face 25 anda pair of wedge Y faces 26`26- converged inwardly ofthe shell andv extending,-preferably, at thes'aine-angle asthe shoe wedge faces 22.

In thenorinal or full release position ofthe' parts, theb'caring face of the` wedgebleclr C is spaced from the front follower let apredetern'iinedi distance-ri depending upoir the` desired amount of easy preliminary action. In actual practice, this space will approximate one-half inch.

The two pressure-transmitting auxiliary Ywedge members D are of like construction and each comprises top and bottom heavy `ilanges sections 2.7-27 (see Figure 5); a longitudinally extending vertical flange se tion 2S and an inclined heavy sections 2), the latter providing an inner wedge face and an outer wedge face 3l co-operable with the wedge faces 2G and 22, respectively. At its inner end, each member D is formed with a fiat transversely extending bearing face which engages the front face of the spring follower H at a point spaced forwardly from the spring follower G a distance at least equal to the distance between the frontend of the wedge block C and the follower 14.. Each member D is suitably braced by a strengthening rib 130 on its outer side, as best shown in Figure 5. In the normal position of the parts, it will be noted that there is considerable clearance between the side faces of the wedge block C and the opposed faces of the auxiliary wedge members D. lt will also be observed that the wedge block C is suitably held in proper central position by engagement between the top and bottom lianges 27 of the two auxiliary wedge members D.

rille retainer bolt il is anchored at its rear end within a suitable hollow boss formed integral with the casting A. and at its `front end in the recess provided in the wedge C, it being understood that the spring follower' H is suitably apertured to accommodate the shank of the bolt, The bolt (l serves to maintain the parts in assembled relation and also to maintain the spring coils under initial compression.

rEhe operation of the mechanism is as follows, assuming a buliing action, pz'irticular reference being had to Figures l and l. As the drawbar l2 and follower la move to- 'ard the right, as viewed in Figure l, thc two a :il iary pressure-transmitting wedge members D will be moved longitudinally, simultaneously therewith. During this action, the shoes B will remain substantially stationary due to the resistance afforded by the heavy outer coil spring E, the normal amountof static friction between said shoes and the surfaces of the shell. and also by reason of the taper of the shell surfaces 18 which further resists tendency of the shoes l5 to move inwardly of the shell. as the two wedge members D are moved longitudinally, they are also compelled to move laterally inwardly toward each other, sliding hetween the sets of wedge faces 22 and 26 of the shoes and wedge member C, respectively. rlliis movement of the members D is resisted, not only by the friction obtaining between the wedge fac-es referred to, but also .ance to absorb the heavier blows.

by the inner coil spring F, acting through the follower H. This action continues until the part-s assume the position shown in Figure et, that is, when the outer ends of the members D are flush with the outer bearing face 25 of the wedge block C. At this time, the wedge members Du and wedge block C are interlocked and in tight engagement with each other, as clearly shown in Figure al, and during the remainder of the compression stroke, act as a solid unit, thus naking the wedge faces 3l of the members D the effective wedge faces in exerting lateral pressure against the shoes B as the latter are forced inwardly of the shell. As the shoes are forced inwardly of the shell, it is evident` that a slight dill'crential action will take place, the shoes B approaching each other laterally, which movement is readily accommodated, inasmuch as there is a space provided for this purpose between the shoes and the inner ends 32 of the wedge members D, as clearly shown by Figure 4. ln release, the initial action is caused by the spring F which bears directly upon the auxiliary wedge members D and serves to loosen the latter with respect to the slices, thus permitting a collapse of the entire friction unit and then permitting both spring coils to expand and restore all of the parts to normal position. As will be evident, compensation for wear will be automatically provided for by the shoes B gradually working outward under the expansion of the outer spring coil E.

By properly proportioning the parts and the space initially left between the wedge block C and the follower la, I am enabled to obtain an easy. relatively light capacity resistance for any desired initial portion of the conipression str-oke which is then followed by a much heavier frictional resist lVith this construction, the mechanism is especially useful on pa sengei' equipment where the greater n'iajo of the shocks are relatively small.

l have herein shown and described what l now consider the preferred manner of carrying out my invention, but the same is merely illustrative and l' contemplate all changes and modifications that come within the scope of the claims appended hereto.

l claim:

l. in a friction shock absorbing mechat nism, the combination with a friction shell having interior opposed frittion surfaces; of a spring resistance; opposed frictionshoes co-operable with said shell surfaces; central wedge-acting means free from direct actuating pressure during the initial portion of a compression stroke but arranged to receive the actuating pressure directly after a predetermined preliminary action; and pressure-transmitting auxiliary wedge` means.,

operable between said first named wedge means and the shoes and adapted for limited` movement with respect to said first named wedge means during said initial portion of the compression stroke.

2. In a friction shock absorbing mechanism; the combination with a friction shell having interior opposed friction surfaces converged inwardly of the shell; of a spring resistance; opposed friction-shoes slidable on the vfriction surfaces of the shell; central wedge-acting` means normally free from direct actuating pressure but adapted to directly receive the actuating pressure after a predetermined compression of the mechanism; and pressure-trausmitting auxiliary wedge means interposed between said first named wedge means and the shoes and adapted for limited movement with respect to said first named wedge means during the initial portion of a compression stroke, the relative movement of said central and auX- iliary wedge means being terminated upon the central wedge coming under direct actuating` pressure. v

In a friction shock absorbing mechanism, the combination with a friction shell having interior` opposed friction surfaces; of a spring resist-ance comprising an inner coil and an outer coil; opposed friction shoes cooperable with the friction surfaces of the shell; pressure transmitting wedge means cooperating with said shoes; and central wedge acting means free from direct actuating pressure during the initial part of a compression stroke; and thereafter adapted to receive the actuating pressure simultaneously with the pressure transmitting wedge means; said pressure transn'iitting wedge means being yicldingly resisted at their inner end by said inner Spring coil and said shoes being directly resisted by said outer spring coil.

il. In a friction shock absorbing mechanism; the combination with a friction shell having interior, inwardly converging` friction surfaces; of a spring` resistance; friction shoes coacting with said shell surfaces; a lateral pressure transmitting unit including a wedge block initially free from the direct actuating force and pressure-transmitting members interposed between the wedge block and shoes, said pressure-transmitting members beingadapted to directly receive the actuating force; said unit being contractalile during the compression stroke; and follower mea-ns (3o-operating with said unit adapted to engage said wedge block after a predetermined compression of the mechanisni and limit the contraction of said unit.

ln a friction shock absorbing mechanism, the combination with aA friction shell having inwardly converging friction surfaces on the interior thereof; of a spring resistance; and a friction generating sys- (5. in a friction shoclr absorbing mecha-A nism; the combination with a friction shell having inwardly conif'erging friction surfaces on the interior thereof; of a plurality of friction wedge shoes `cti-operable with said shell friction surfaces; a spring resistance; an outer centractible wedge coacting with saidv friction slices; and an inner wedge co--operable with said outer wedge; said outer wedge being provided with abutn'ient faces adapted to limit the contraction thereof by engagement with said inner wedge.

7. In a friction shock absorbing mechanism; the combination with a front follower; of a friction shell having inwardly converging friction surfaces on the interior thereof; a plurality of friction wedge shoes co-operable with said shell friction surfaces; a spring resistance; an outer contractible wedge counting with said front follower and engaging said shoes; an inner wedge within said contractible wedge and co-operable therewith; said inner wedge having` the outer end normally spaced from said follower and adapted to be engaged thereby after a predetermined action of the mechanism and moved inwardly of the shell in unison with said outer wedge.

8. lu a friction shock absorbing mechanism, the combination with a front follower; of a friction shell having inwardly converging friction surfaces on the interior thereof; of a plurality of friction wedge shoes cooperable with said shell friction surfaces; a spring resistance; an outer contractible wedge enacting with said front follower and engaging said shoes; an inner wedge within said contractible wedge and co-operable therewith; said inner wedge having` its outer end normally spaced from said follower and adapted to be engaged thereby after a predetermined action of the mechanism and moved inwardly ofthe shell in unison with said outer wedge; coacting abutment means on seid outer and inner wedges; and means for limiting the outward movement of said inner wedge.

9. ln a friction shock absorbing mechanism, the combination with a friction shell having inwardly converging friction surfaces on the interior thereof; of a plurality of friction wedge shoes co-acting with said shell friction surfaces; a contractible outer wedce coacting with said shoes; an inner wedge coacting with said contractible wedge lilil and acting to limit the contract-ion of the latter; and spring resistance means opposing inward movement of said contractible Wedge and shoes. Y

l0. lin a friction shock absorbing` mecha.- nism, the combination With a friction shell having interior inwardly converged friction surfaces; of a spring resistance; Wedge friction shoes co-operable With the surfaces oi' said shell; a direct pressure-receiving, contractible and expansible Wedge co-oper able with said shoes; and an auxiliary Wedge co-operable with said first named wedge and initially tree from actuating pressure, but arranged to receive the actuating pressure directly after a predetermined preliminary action.

ll. In a friction shock absorbing,` mechanism, the combination with a colunnracting friction member having longitudinally ez;- tending friction surfaces; of a spring resistance; Wedge friction slices co-operable with the friction surfaces of said member; a sectional wedge co-operable With said shoes and adapted to directly receive the actuating pressure; and auxiliary Wedge means co-operable with said sectional Wedge, said auxiliary wedge means being free from direct actuating pressure durin` the initial portion oft the compression stroke and thereafter adapted to receive the actuating pressure simultaneously with the sectional Wedge, the latter and the auxiliary Wedge means then acting as a single unit.

In Witness that I claim the 'foregoing l have hereunto subscribed my name this (Sth day ot' July, 1923.

JOHN F. OCONNOR. 

